IT is only fitting that the extraordinary political year would give way to the season of the political biopic. With terse titles that grandly promise the last word on their subject, Gus Van Sant’s “Milk,” Oliver Stone’s “W.” and Steven Soderbergh’s “Che” all deal with once- (or still-) incendiary political figures.

While the films bear a strong directorial point of view, the directors also worked with screenwriters who laid the groundwork for wrangling a life into the shape of a narrative. The writers — Dustin Lance Black (“Milk”), Stanley Weiser (“W.”) and Peter Buchman (“Che”) — each went through a similar gantlet of intensive research but often arrived at different solutions when it came to the conundrums of biography: how to get at the private truth beneath the public person and how to reconcile the conflicting roles of fact checker and myth maker.

“Milk,” which charts the inspirational rise of the assassinated gay-rights advocate Harvey Milk, is a classical biopic, running through a greatest-hits version of its subject’s life and career with an eye on both his historical importance and his enduring relevance. The two-part, four-hour-plus “Che” celebrates Ernesto Guevara not by romanticizing what the man fought for but by systematically restaging the battles that he fought. And while the other two films summon their dead heroes from the mists of memory, “W.,” a speculative peek into the formative psychology of George W. Bush, is more like an early draft of history, rushed into theaters while the president’s legacy was still up for grabs.

Of the three screenwriters Mr. Black had perhaps the least complicated task, in the sense that his feelings about his subject were the most clear cut. A gay man raised in a Mormon family, he recalls hearing about Milk as a high school freshman in the ’90s, having just moved to the Bay Area from San Antonio. “To find out there was an out gay man who was celebrated really was shocking,” Mr. Black said.

After graduating from film school at the University of California, Los Angeles, he worked as a reality-television director and as a writer for “Big Love,” the HBO series about a polygamous Mormon family. The idea for a Harvey Milk biopic came about in 2004, when a friend asked him to collaborate on a rock opera about Cleve Jones, a protégé of Milk’s and a creator of the AIDS memorial quilt project.

As Mr. Jones described his relationship with his mentor, Mr. Black was reminded of his own investment in the story. “I was abandoned by my father at a young age, and so I was drawn to Harvey as a father figure,” Mr. Black said. “That was Cleve’s story too. He lived the life I dreamed of — moved to San Francisco and met this man who was very paternal to him, pulled him off the streets and taught him to become an activist.”

Milk’s life was previously chronicled in Rob Epstein’s Oscar-winning documentary “The Times of Harvey Milk” (1984), and Randy Shilts’s biography, “The Mayor of Castro Street” (1982), was optioned for a film adaptation, a project that kicked around for years but never got off the ground. (Mr. Stone and Mr. Van Sant were among the interested directors.) Only dimly aware of this rival project’s tortuous history, Mr. Black embarked on his script without a producer or director attached.

He began by familiarizing himself with the political terrain of San Francisco in the ’60s and ’70s: the rise of liberation politics and the shift from citywide to district ballots that paved the way for Milk’s election to the board of supervisors. But the meat of the story would have to come from the firsthand accounts of Milk’s friends and colleagues, many of whom had qualms about sharing their reminiscences with — or being turned into movie characters by — an untested young writer.

Mr. Black relied on the introductions of Mr. Jones (who was also his conduit to Mr. Van Sant). “It took a lot of convincing,” Mr. Black said. “They had been through it with other film projects. These people didn’t want to be disappointed again.” Mr. Black said that Michael Wong, an adviser to Milk who kept a diary of their interactions, later told him, “That wasn’t you interviewing us, that was us interviewing you.”

He ended up talking to some 40 people, including Anne Kronenberg, Milk’s campaign manager (now a San Francisco public health official), and Danny Nicoletta, a photographer who worked in Milk’s camera store. Because his subjects were often recounting decades-old moments that were semi-forgotten or had calcified into myth, Mr. Black developed a strategy of pairing them up, “so they could correct each other,” he said.

The goal was to arrive at a portrait of a sainted martyr, scaled to human dimensions. “The legend of Harvey Milk was fantastic, but the real Harvey Milk, the screwed-up guy who told corny jokes at the wrong time, was even better,” Mr. Black said.

Mr. Soderbergh and the screenwriter Mr. Buchman took a different approach to humanizing their larger-than-life figure. Since Guevara has become a free-floating symbol, they made a film that functions as a counterweight, rooted in concrete minutiae and tactile experience. “Steven wanted it to feel like we were looking over their shoulders, like you’re in the jungle with these guys,” Mr. Buchman said.

Mr. Soderbergh added: “The shape of the film was determined by what we didn’t want to do. I didn’t want to deal with his personal life, and I wasn’t interested in him as a bureaucrat.” Far from a conventional biopic, “Che” takes shape as a scrupulous procedural on guerrilla warfare.

It took a few go-rounds for the film to arrive at its current bifurcated form. The project had long been in development by the producer Laura Bickford and Benicio Del Toro, who plays the title role and also produced, with Terrence Malick set to direct at one point. The initial idea was to dramatize a relatively underexplored chapter of Che lore: his doomed Bolivian expedition in 1966.

An error has occurred. Please try again later.

You are already subscribed to this email.

When the film was revived a few years ago, now with Mr. Soderbergh directing, Mr. Buchman, whose credits include “Jurassic Park III,” became involved. Along with Mr. Del Toro, they decided to juxtapose the failed Bolivian insurrection with the successful Cuban revolution that had taken place a decade earlier. “We were seeing the fall of the man without seeing his rise,” Mr. Buchman said. Without Cuba, Mr. Soderbergh said, “Bolivia looked purely like an exercise in futility.”

The filmmakers also opted to fold in two other episodes: Guevara’s initial meeting with an exiled Fidel Castro in Mexico City in 1955 and his visit to New York in 1964, during which he faced the news media and addressed the United Nations. “It was an opportunity for him to talk about ideology in an organic way,” Mr. Soderbergh said of the New York scenes. “I didn’t want him standing around the jungle pontificating.”

Mr. Buchman came up with a 150-page script that entwined four timelines and would make for a two-and-a-half-hour film. But with production looming, it became clear to Mr. Soderbergh that the movie “had to divide in order to survive.” He proposed two movies that would deal separately with Cuba and Bolivia. One radical revision later, the film had split into mirror-image halves, with Mexico and New York woven into the Cuban odyssey of “Part One.” (Mr. Buchman is the sole writer credited for “Part One”; on “Part Two” he shares credit with Benjamin A. van der Veen, who worked on an earlier version.)

Guevara’s diaries were an important source, but as with Mr. Black’s process for “Milk,” it was the interviews that proved decisive. Mr. Buchman, Mr. Soderbergh and Mr. Del Toro traveled to Cuba several times and talked to Guevara’s family and friends, generals who fought in the Cuban revolution and survivors from the Bolivian expedition. Che’s widow, Aleida, who was by his side during the pivotal battle of Santa Clara (recreated at length in the movie), walked the filmmakers through the actual site. (Mr. Buchman’s script was submitted for Oscar consideration as an original screenplay, but the Academy of Motion Picture Arts and Sciences has ruled that it is adapted. “Milk” and “W.” will be considered in the original-screenplay category.)

In stark contrast to the just-the-facts method of “Che,” Mr. Stone and his screenwriter, Stanley Weiser, made a movie about motivation, rooting about in the presidential psyche to ask what drove Mr. Bush first to seek the highest office in the land and then to lead the country into war.

The movie offers twin Rosetta stones: Mr. Bush’s competitive relationship with his father and his born-again Christianity. “The plan was to triangulate father, God and war,” Mr. Weiser said.

Instead of formulating a new take on the man, they synthesized existing ones. Mr. Weiser sampled from the cottage industry of insider tell-alls that has sprung up around the Bush administration. He read and marked up 21 books, ripping out pages and compiling a dossier of key events. The titles ranged from Mr. Bush’s own memoir, “A Charge to Keep,” to Bob Woodward’s series of increasingly critical behind-the-scenes accounts. To depict Mr. Bush’s religious conversion, Mr. Weiser drew on Stephen Mansfield’s “Faith of George W. Bush.” Books like James Hatfield’s “Fortunate Son” and Kitty Kelley’s “Family” helped fill in the Oedipal drama.

Mr. Stone and Mr. Weiser, who worked together on “Wall Street” (1987), have made no secret of their political inclinations — both are openly disdainful of the president — but they were determined to paint a temperate, even empathetic portrait. Having been the screenwriter of “Rudy,” a television biopic of Rudolph W. Giuliani, Mr. Weiser said, “I had been primed to be able to write about characters I may find reprehensible.”

Released as the 2008 presidential campaign neared its climax, “W.” ended up assuming its subject’s lame-duck aura. (The domestic box office gross was an underwhelming $25 million.) It did not help, Mr. Stone said, that the movie confounded expectations: “People wanted me to shoot fish in a barrel. But as dramatists it’s our job to cross over into this world where we are Bush and we have to look in the mirror and say, ‘Hey, you’re a good guy.’ ”

Mr. Stone has tackled political figures before (“Nixon” and a documentary about Castro), but he considers Mr. Bush a singular challenge for biographers. “I don’t think he has an inner life,” Mr. Stone said.

In most cases the process of making a biopic seems only to have heightened the filmmakers’ sensitivity to the inherent problems of biography. Mr. Soderbergh, for one, said he believes the answer is to rethink the form every time out.

“The fact that time moves in one direction implies a narrative,” he said. “In order to get up every morning and not go bananas, we apply an organized template over what’s going on to make it seem like there’s a structure. But there are days when I feel that’s absolutely not true. For this film we were thinking about what it would mean to show a life, rather than tell a story.”